Chemistry Review - Concentration These should be fairly quick. Write out unit conversion calculations for full credit (don't use online unit conversion except to check your answer). 1. (4 pts; SMP 9.3] The average carbon dioxide content in ambient air is 0.03 percent on a mole fraction basis. Express the concentration in ppm and mg/L, assuming standard conditions of 1 atm pressure and O'C. 2. [3 pts] You want to make 500 mL of a 75 ppm solution of ammonia. How many milligrams of ammonia should you use? 3. (3 pts; SMP 9.5) If 1000 lbs of lime are added to 1.00 million gallons of water, what is the concentration of the lime in mg/L? 4. [3 pts; SMP 9.6] The PCB content of a soil is found to be 8 ppm. If the density of the soil is 2 kg/m', what is the PCB content in grams per cubic meter of soil? 5. (3 pts; SMP 9.14) The EPA maximum contaminant level (MCL) for trichloroethene (TCE) in drinking water is 5 mg/L. The specific gravity of pure TCE (a liquid) is 1.46. What volume of TCE in milliliters would need to be added to 200 million gallons of water (about the daily drinking water supply for 1 to 2 million people) to increase the TCE concentration by 5 mg/L? Risk Assessment 6. [4 pts) Analysis of lake water reveals concentrations of 5 ppb Aldrin and 5 ppb Chlordane. Estimate the concentration of each constituent expected in fish in mg/kg. *Note that the units are wrong in Table 3-6; the BCF should be in L/kg.* 7. (12 pts] Soil at a residence is contaminated with 7 mg/kg of Dieldrin (an insecticide). Assume people are exposed to soil 2 days/wk, the fraction of Dieldrin ingested is 0.1 and you assume a 1-year averaging time. Calculate and compare the CDIs for: a. A 5-year-old child b. An adult female c. An adult male d. Which of these three would be at the most risk? Least risk? Explain. 8. [12 pts] A city water supply is found to contain 3 ug/L of arsenic. The air concentration is estimated at 3 kg/m while showering. For an adult woman: a. Calculate the CDI for oral consumption of drinking water b. Calculate the CDI for inhalation if she takes a daily 30 minute shower c. Which of these activities results in a higher risk? Explain your answer. 9. [6 pts] Calculate the hazard index for an oral CDI of 0.002 mg/kg:d for the following: a. Barium b. Cadmium c. Which of these compounds is more likely to affect human health? Explain